Dr. Paul Deglmann
Meghan Feir Walker
Have you ever wondered why you feel wide awake at 10 p.m. but struggle to get out of bed the next morning, or why your energy crashes every afternoon despite getting what seems like enough sleep? It could be due to cortisol and circadian rhythm issues.
Many people assume these issues are simply the result of high cortisol or low cortisol. But in reality, the bigger question is whether or not your cortisol is being released in the right amounts at the right times throughout the day.
Your body is designed to follow a predictable 24-hour biological clock known as your circadian rhythm. One of the most important hormones controlled by this clock is cortisol. While cortisol has earned the nickname "the stress hormone," its role extends far beyond responding to stressful situations. It helps regulate your energy, metabolism, blood sugar, immune function, blood pressure, and your sleep-wake cycle every single day.¹
When your body's natural rhythm becomes disrupted by chronic stress, poor sleep, shift work, blood sugar imbalances, inflammation, or other underlying health issues, you may begin noticing patterns such as fatigue, difficulty sleeping, brain fog, or feeling wired but tired. These symptoms don't necessarily mean your cortisol is simply too high or too low. They often indicate that your cortisol circadian rhythm is no longer functioning the way it should.
At Restorative Health Solutions, we believe in a simple philosophy:
“Test, don't guess.”
Rather than assuming cortisol is the problem, we work to identify why your daily rhythm has become disrupted in the first place. Addressing the root cause, and not just the symptom, is the foundation of functional medicine.
Key Takeaways
- Cortisol follows a predictable 24-hour rhythm, rising before and shortly after waking and gradually declining throughout the day.
- Healthy cortisol is about proper timing, not simply having high or low cortisol.
- Chronic stress, poor sleep, blood sugar instability, inflammation, and irregular schedules can disrupt this natural rhythm.
- Evaluating the entire daily cortisol pattern often provides more meaningful information than a single cortisol measurement.
- Functional medicine focuses on identifying and addressing the root causes contributing to cortisol dysregulation rather than simply masking symptoms.
What Is Cortisol?
Cortisol is a hormone produced by your adrenal glands, two small glands located on top of your kidneys. Although it's commonly referred to as the "stress hormone," that description only tells part of the story.
Even on your most relaxing vacation, your body is producing cortisol.
That's because cortisol helps regulate many of the body's most important daily functions, including:
- Maintaining healthy blood sugar levels
- Supporting normal blood pressure
- Helping convert stored nutrients into usable energy
- Regulating inflammation and immune activity
- Supporting mental alertness and focus
- Coordinating the body's sleep-wake cycle
Think of cortisol as your body's natural daytime hormone. It helps you meet the demands of the day by making energy available exactly when you need it.
The goal isn't to eliminate cortisol. In fact, healthy cortisol is essential for good health.¹ Problems arise when cortisol is produced at the wrong times, in the wrong amounts, or when the body's daily rhythm becomes disrupted.
Understanding the HPA Axis
Cortisol doesn't operate independently.
Its release is controlled by a communication network known as the hypothalamic-pituitary-adrenal (HPA) axis.¹
The hypothalamus in your brain constantly receives information about your environment, including light exposure, sleep patterns, emotional stress, inflammation, blood sugar levels, illness, and physical activity. It communicates with the pituitary gland, which then signals the adrenal glands to release cortisol.
Rather than thinking of cortisol as simply an adrenal hormone, it's more accurate to think of it as the final messenger in an incredibly sophisticated communication system.
When this system functions properly, cortisol rises and falls according to your body's internal clock. When chronic stressors continue day after day, this communication network can gradually lose its normal rhythm.
This is why functional medicine doesn't simply ask, "What's your cortisol level?"
Instead, we ask, "Why has your body's stress response become disrupted?"
How Cortisol Follows a Circadian Rhythm
Your body is designed to release cortisol according to a very predictable daily schedule.
During the night, cortisol remains relatively low, allowing melatonin to promote restful sleep.
Several hours before you wake up, cortisol begins rising naturally. Shortly after waking, it reaches its highest point before gradually declining throughout the remainder of the day.
Imagine standing on the beach watching a wave slowly rise before sunrise, crest during the early morning, and gradually roll back toward shore throughout the afternoon and evening. That's very similar to what a healthy cortisol curve looks like.
This natural cortisol circadian rhythm is synchronized by a tiny structure deep within the brain called the suprachiasmatic nucleus (SCN), often referred to as the body's master clock.
The SCN receives information from your eyes about light exposure and uses that information to coordinate hormone production, body temperature, metabolism, digestion, and sleep.
When sunlight enters your eyes in the morning, it helps reinforce this daily rhythm, signaling your brain that it's time to be awake, alert, and energized.²³
The Cortisol Awakening Response
One of the most important parts of the daily cortisol cycle is the cortisol awakening response (CAR).
Approximately 30 to 45 minutes after waking, cortisol rises rapidly before reaching its daily peak.⁴
This temporary increase isn't a problem. It's actually a sign that your body is preparing you for the day ahead.
A healthy cortisol awakening response helps promote:
- Mental alertness
- Physical energy
- Blood sugar regulation
- Focus and concentration
Poor sleep, irregular wake times, chronic stress, shift work, or circadian disruption may blunt or delay this normal morning rise.⁴
Someone experiencing a reduced morning cortisol response often describes feeling as though they can't get going until late morning or early afternoon, even after sleeping through the night.
The Cortisol-Sleep Connection
The relationship between cortisol and sleep works both directions.
Healthy cortisol rhythms help you feel alert during the day and sleepy at night.
At the same time, getting restorative sleep helps maintain a healthy cortisol rhythm.
When sleep becomes disrupted, cortisol patterns often become disrupted as well.³⁵
Many people with an altered rhythm describe patterns like:
- Difficulty falling asleep despite feeling exhausted
- Waking between 2-4 a.m.
- Feeling groggy in the morning
- Afternoon energy crashes
- Feeling unusually alert late at night
Notice that these are patterns, not diagnoses.
Recognizing these patterns simply helps identify areas that deserve further investigation.
Melatonin and Cortisol: Partners in the Sleep-Wake Cycle
If cortisol is your body's daytime hormone, melatonin is its nighttime counterpart.
As daylight fades, cortisol naturally declines while melatonin begins increasing.
This carefully coordinated handoff allows your brain and body to transition toward restorative sleep.
Unfortunately, modern lifestyles frequently interfere with this process.
Bright indoor lighting, television, smartphones, tablets, laptops, inconsistent sleep schedules, and late-night work can all confuse the body's internal clock.
The result is often a delayed melatonin release and an equally delayed decline in cortisol.
Instead of feeling sleepy at bedtime, people frequently describe feeling "wired but tired."²³
Why Cortisol Timing Matters More Than Cortisol Amount
One of the biggest misconceptions surrounding cortisol is the belief that it's simply either high or low.
In reality, timing is often more important than the absolute number.
Two individuals may produce similar total amounts of cortisol over a day but have completely different daily patterns.
For example, someone might experience:
- Low cortisol in the morning
- Elevated cortisol late at night
- A flattened cortisol curve throughout the day
- An exaggerated or blunted morning cortisol awakening response
Each pattern may produce very different symptoms.
This is one reason why evaluating the entire cortisol circadian rhythm can be much more informative than relying on a single measurement.
What Happens When This Rhythm Gets Disrupted?
Numerous factors can interfere with your body's natural clock.
These include:
- Chronic emotional stress
- Inconsistent sleep schedules
- Shift work
- Frequent travel or jet lag
- Blood sugar instability
- Chronic inflammation
- Pain
- Illness
- Gut dysfunction
- Certain medications
Over time, these stressors can gradually shift or flatten the normal cortisol curve.
People often begin noticing patterns such as:
- Difficulty waking
- Mid-afternoon fatigue
- Brain fog
- Cravings for sugar or caffeine
- Poor exercise recovery
- Trouble falling asleep
- Nighttime awakenings
- Feeling energized late at night
Again, these patterns don't automatically point to one diagnosis. They simply suggest that your body's daily rhythm may deserve a closer look.
Common Disruptors: Stress, Irregular Sleep, and Night-Shift Work
One of the clearest examples of circadian disruption is night-shift work.
Your brain receives light signals telling it that it's daytime, while your work schedule tells it to remain awake overnight.
These conflicting signals make it difficult for cortisol and melatonin to stay synchronized.⁶
Although less dramatic, a similar effect occurs with:
- Staying up much later on weekends
- Frequent travel across time zones
- Rotating work schedules
- Sleeping in several hours on days off
Even relatively small changes in sleep timing can gradually shift the body's internal clock.
Signs Your Rhythm May Be Out of Balance
Some patterns worth discussing with a qualified healthcare practitioner include:
- Feeling exhausted in the morning
- Needing multiple cups of coffee just to function
- Afternoon energy crashes
- Feeling more productive late at night
- Difficulty falling asleep despite fatigue
- Waking during the night
- Persistent fatigue despite adequate sleep
These aren't intended as a self-diagnostic checklist.
Instead, they can help identify whether further evaluation may be appropriate.
A Functional Medicine Approach to Restoring Your Rhythm
In conventional medicine, cortisol is often evaluated with a single blood draw.
While blood testing certainly has an important place in medicine, it only provides a single snapshot of a hormone that changes dramatically throughout the day.
At Restorative Health Solutions, we take a different approach.
We believe in taking a “Test, don't guess” approach to health.
Rather than only asking whether cortisol is high or low, we ask:
- Is your morning cortisol rising appropriately?
- Does your cortisol gradually decline throughout the day?
- Is it remaining elevated at night?
- What underlying factors are disrupting this rhythm?
More importantly, why?
Is chronic stress driving the problem?
Could blood sugar instability be triggering nighttime cortisol release?
Is poor sleep disrupting the body's internal clock?
Could chronic inflammation, gut dysfunction, nutrient deficiencies, or other underlying stressors be keeping the HPA axis activated?
Instead of simply trying to raise or lower cortisol, functional medicine seeks to identify and address the factors that are disrupting levels in the first place.
Functional Lab Testing
One of the strengths of functional medicine is evaluating hormones according to how they naturally behave.
Because cortisol changes continuously throughout the day, collecting multiple samples provides a much clearer picture than a single measurement.
For this reason, multi-point salivary cortisol testing is one of the most clinically useful ways to evaluate a person's daily cortisol rhythm.⁷
Saliva measures free (biologically active) cortisol at several points throughout the day while you're in your normal environment.
This provides valuable insight into the overall shape of your cortisol curve, including your morning rise, afternoon decline, and evening levels.
By comparison, a single blood cortisol measurement represents only one moment in time. It may miss abnormalities in the daily rhythm, and obtaining multiple blood samples throughout the day is often impractical. Additionally, for some individuals, the stress associated with traveling to a laboratory, waiting for testing, or undergoing a blood draw may temporarily elevate cortisol levels, potentially making interpretation more challenging.⁸
At Restorative Health Solutions, we frequently utilize the Adrenocortex Stress Profile (ASP) to evaluate the daily cortisol rhythm. In certain situations, additional testing such as the DUTCH test may provide complementary information about cortisol metabolism and other hormone pathways.
The Endocrine Society also recognizes late-night salivary cortisol as one of the recommended first-line screening tests for Cushing syndrome when clinically appropriate.⁹
The goal is never to chase lab numbers.
The goal is to understand how your body is functioning so that treatment can be personalized to your unique physiology.
That's what we mean when we say we take a “Test, don't guess” approach in discovering your individual patterns and needs.
Root-Cause Lifestyle Strategies
Lifestyle plays a powerful role in regulating your internal clock.
Some of the most effective lifestyle strategies for supporting and improving cortisol levels include:
Getting Morning Sunlight
Aim to get outside within the first hour after waking whenever possible.
Natural light helps reinforce your circadian rhythm and supports a healthy morning cortisol rise.
Maintaining a Consistent Sleep Schedule
Going to bed and waking up at approximately the same time each day helps synchronize your body's internal clock.
Reducing Evening Light Exposure
Dim lights during the last one to two hours before bed and reduce screen exposure whenever possible to support melatonin production.
Supporting Healthy Blood Sugar
Eating balanced meals with adequate protein, healthy fats, and fiber can help minimize blood sugar swings that may contribute to nighttime cortisol elevations.
Moving Your Body
Regular movement supports healthy circadian signaling, especially when performed earlier in the day.
Practicing Stress Management
Breathing exercises, prayer, meditation, spending time outdoors, and other restorative practices can help reduce the cumulative effects of chronic stress on the HPA axis.
Small, consistent habits often produce bigger long-term improvements than dramatic short-term changes.
How Restorative Health Solutions Can Help
Your body's daily cortisol rhythm is one of the foundations of healthy energy, restorative sleep, balanced metabolism, and resilience to stress.
When that rhythm becomes disrupted, the solution isn't simply to lower cortisol or raise cortisol. The goal is to understand why the rhythm changed in the first place.
That's the heart of functional medicine.
At Restorative Health Solutions, we understand that cortisol is rarely the true root cause of health issues.
Instead, it often serves as a messenger, reflecting deeper imbalances involving sleep, stress physiology, blood sugar regulation, gut health, inflammation, nutrient status, and circadian biology.
Our functional medicine approach is designed to connect these pieces together rather than treating each symptom in isolation.
Using comprehensive health histories, advanced functional laboratory testing when appropriate, and individualized treatment plans, we work to identify why your cortisol rhythm has become disrupted so we can help restore normal function from the ground up.
If you've been struggling with fatigue, poor sleep, feeling wired at night, difficulty managing stress, or other patterns that suggest your daily rhythm may be off, a root-cause evaluation may provide the answers you've been searching for.
Learn more about our functional medicine approach.
Ready to Discover What’s Driving Your Symptoms?
At Restorative Health Solutions, we believe in looking beyond symptoms, identifying the underlying contributors to health concerns, and creating personalized plans based on objective testing—not guesswork.
If you're ready to discover what's really driving your symptoms, we'd love to help.
Request your free 15-minute phone consultation today and learn how our root-cause, functional medicine approach can help you restore your health naturally.
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